Dr. Christie's GPS and Geocaching Guide for Educators

Technology is an integral and growing part of daily living in the twenty-first century. The challenge, then, for teachers, is to use technology effectively in classrooms to help students take ownership for learning and develop the practical and critical thinking skills necessary to better understand the world around them.

To meet this challenge, teachers can use an emerging technology tool, GPS receivers, and an emerging GPS-based activity, geocaching, to transform their classrooms from teacher-centered environments to exciting, empowering, exploratory environments that focus on student engagement in the learning process.

GPS is a Satellite Navigation System

The Global Positioning System is a $12 billion system of 24 satellites (plus a few spares) deployed and maintained by the U.S. Department of Defense (DOD). Each satellite passes around the earth twice in a 24-hour period at an altitude of about 12,500 miles. The satellites continuously broadcast position and time data to users throughout the world.

Deployment of the satellites began in 1978, and the system became fully operational (uninterrupted global coverage) in 1995. GPS provides satellite signals that can be processed in a GPS receiver, enabling the receiver to compute one's position on the face of the earth (often indicated in terms of latitude and longitude). Four GPS satellite signals are used to compute positions in three dimensions, so your altitude is also indicated on your GPS receiver.

Global Positioning System

Global Positioning System (GPS) receivers are used in cars, boats, airplanes, and even in cellular phones. Handheld GPS receivers are carried by hikers, surveyors, map makers, and others who need to know where they are. The GPS device receives data from the closest satellites, triangulating data to determine the unit's exact location (typically in latitude and longitude), elevation, speed, and time.

Selective Availability, which made the civil use of GPS less accurate than the military GPS, was turned off on May 1, 2000. Thus, the inexpensive GPS receivers available to civilians are as accurate as those used by the military today. Currently, there are millions of civilian users of GPS and GPS receivers world-wide.

GPS Receivers

A GPS receiver communicates with GPS satellites to provide information to its user. A standard GPS receiver will place the user's location on a map at any given location using latitude and longitude coordinates. It will also trace the user's path from one location to another. With this information and its built-in clock, the receiver can give the user the following information:

How far you've traveled (odometer)

How long you've been traveling

Your current speed (speedometer)

Your average speed

A "bread crumb" trail showing you exactly where you have traveled on the map

The estimated time of arrival at your destination if you maintain your current speed

Geocaching

Geocaching is an entertaining adventure game for GPS users. Participating in a cache hunt is a good way to take advantage of the wonderful features and capability of a GPS unit. The basic idea is to have individuals and organizations set up caches all over the world and share the locations of these caches on the Internet. GPS users can then use the location coordinates to find the caches.

Once found, a cache may provide the visitor with a wide variety of rewards. All the visitor is asked to do is if they get something they should try to leave something for the cache.

Geocaching Photos

Dr. Christie uses GPS receivers and geocaching activities in her graduate classes at Arizona State University. To view any of her classes in action, click on a link below and then scroll through the photo gallery. To view the larger version of any photo, simply double-click on that photo.